Vacuum pulsator valves

ABSTRACT

A vacuum pulsator valve for milking machines is disclosed comprising a pair of valves controlling the alternate application of vacuum and air pressure in a line connected to the pulsator the pulsator including adjustable bleed valves operative to control the frequency of alternation and/or the phase length of alternation of vacuum and air pressure. The pulsator may be subject to compressed air or atmospheric air, and the bleed valves are adjustable externally of the pulsator body.

This application is a division of application Ser No. 349,153, filedFeb. 16, 1982, now abandoned.

The invention relates to vacuum operated pulsator valves for use withmilking machines adapted to be wholly automatic in use.

To assist in the understanding of the present invention the varioustypes of pulsators commonly used will be defined.

1. MASTER AND SLAVE PULSATOR

2. AUTOMATIC PULSATOR

3. RELAY PULSATOR

4. PULSATOR TYPES: REVERSING. NON-REVERSING.

Master and Slave pulsation indicates that all bail pulsators receive andare driven by the actuating vacuum/air pulse generally supplied from amechanical master pulsator driven from the vacuum pump. In this systemthe air demand is balanced by having the pulsators operating in opposingbanks of units so that when one bank is on vacuum the other is on air.This is accomplished by the use of a reversing pulsator, or pulsatorsinstalled at intervals, or by direct linkage from the master pulsator.

Automatic pulsators do not require a master. Initially they arebasically designed to produce, at requisite mercury levels a definedpulse, the rate or speed of which is either fixed or adjustable bycontrolling the volume interchange to a timing chamber of the vacuum/airphases produced by the pulsator. Present type automatic pulsators have aless stabilinsing effect on air line vacuum as having no master control,all pulsators operate more or less at random. Broadly automaticpulsators fall into two types:

(i) Those pulsators designed to produce purely pneumatically atrequisite mercury levels a defined ratio of pulsation of vacuum toatmospheric pressure, the rate or speed of the said pulsation beingregulated by the controlled interchange to a timing chamber, either byfixed jet or adjustable valvular means of the vacuum/air phases producedby pulsator action.

(ii) Those developed on the so-called windscreen wiper principlecombining both pneumatic and mechanical features. These are based onpneumatically operated opposing diaphragms which alternatively andmechanically actuate a spring loaded plastic slide switch-overarrangement which in turn controls the admittance of vacuum oratmosphere to the opposing diaphragms and also to the slide controlledports giving access to and the resultant pulse to the teat cups.

Both in construction and performance these pulsators are more or lessstereotyped and none are capable of performing other than the fixed rolein milking machine pulsation for which they were designed.

Relay pulsation on milking machines is defined as where the first bailpulsator receives its actuating pulse direct from a "Master" and then inturn relays the pulse received to the next pulsator and so on. Thismeans that the vacuum/air phases "ripple" along the air-line thusstabilising the vacuum variation in the line to a greater extent than inthe balance effect of Master and Slave pulsation.

Pulsator types; Reversing and non-reversing.

The reversing pulsator is so called because it delivers the oppositepulse to that received, i.e: upon receiving an air pulse to itsactuating chamber it delivers a vacuum pulse to the teat cups and inrelay pulsation-also to the next pulsator and vice versa.

The non-reversing pulsator upon receiving an air pulse, delivers an airpulse and vice versa.

In all known pneumatic relay pulsators controlled by an automatic masterthe passing of pulsation phases one to the other has only beeneffectively accomplished when the pulses passed were of an equal ratio.In the circumstances where a master or a relay pulsator produces anoperating pulse where the vacuum phase is greater than that ofatmospheric pressure such as a vacuum/air ratio of 60:40, then thispulse would, if passed directly to the actuating chamber of the nextpulsator, produce to the connected teat cups of that pulsator thereversed vacuum/air ratio of 40:60.

There is no known milking machine valve capable of correcting thiseffect and enable in such pulsation the passing one to the other of anydesired constant ratio.

This invention relates to both reversing and non-reversing type vacuumoperated pulsator valves for use with milking machines adapted to bewholly automatic in use. Preferably the invention will be described withreference to a reversing type pulsator i.e: a pulsator which onreceiving an air pulse to its timing or to its actuating chamber,produces an ensuing vacuum pulse to its attached teat cups and viceversa.

It is the principal objective of the invention to provide a pulsatorvalve for milking machines which is readily adjustable as to rate ofpulsation and also as to the ratio of pulsation of vacuum to bothatmospheric and compressed air pressure as required.

It is also an objective of the invention to provide:

1. a master or control pulsator for operating a plurality of slavepulsators;

2. a relay from pulsator to pulsator under master control reversible ornon-reversible;

3. as a master and slave combination; or

4. as an automatic unit operating as a milking medium direct to teatcups.

5. A pulsator with externally mounted control valves and a timingchamber with external access to the vacuum/air pulses received. Thevalves are flexibly connected to timing chambers.

It is also an objective of the invention to provide:

a pulsator valve also having incorporated, or may have as a separateattachable unit, readily adjustable valvular means enabling it at thesame time, or independently, to be used as a master pulsator for thetransmitting or relaying of any desired pulsation ratio;

a relay pulsator valve having incorporated or attached similaradjustable valvular means as in the preceding paragraph of readilyadjusting in step or out-of-step pulsation ratios to any desiredconstant ratio;

a pulsator valve as in the preceding paragraph also designed to act as aversatile reversing or balancing pulsator between those opposing banksof pulsators that are so disposed in master and slave pulsation operatedmilking machines in order to balance air demand;

a highly efficient slave pulsator suitable for either mechanical orautomatic master control;

the pulsator valve as in preceding paragraphs eminently suitable for usewith compressed air in lieu of atmospheric air as the pressure medium tothe teat cups;

valvular means as described (see FIG. 4) which may be used independentlyas a means of converting other types of slave or relay pulsators to anydesired ratio of pulsation.

According to the present invention there is provided a vacuum pulsatorcomprising a body for housing a pair of valves sealingly mounted withinthe body, one valve being moved alternately to the other valve betweentwo positions to control a bleed means, said bleed means communicatingwith the other valve for alternately applying vacuum and pressure tosaid other valve, said bleed means including adjustable meanscontrolling the ratio of the pulsator cycle and thereby controlling thelength of time said valve is subjected to vacuum or pressure.

Conveniently the adjustable means is a needle valve associated with thebleed means controlling the volume of fluid to said other diaphragm.

According to a further aspect of the invention adjustable additional airor vacuum bleed means are provided operable to vary the rate orfrequency of the pulsator cycle viz. by varying the rate of alternationof said valves.

The invention will be described in greater detail having reference tothe accompanying drawings in which:

FIG. 1 is a sectional view of a master pulsator taken on line II--II ofFIG. 2.

FIG. 2 is a plan view of FIG. 1.

FIG. 3 is a sectional view of a relay pulsator taken on line III--III ofFIG. 7.

FIG. 4 is a sectional view taken on line IV--IV of FIG. 2.

FIG. 5 is a sectional view taken on line V--V of FIG. 2.

FIG. 6 is a sectional view of ratio adjusting mechanism taken on lineVII--VII of FIG. 7.

FIG. 7 is a plan view of a relay pulsator.

FIG. 8 is a sectional view of the relay pulsator taken on lineVIII--VIII of FIG. 7.

FIG. 9 is a sectional view of a pressure member taken on line IX--IX ofFIG. 10.

FIG. 10 is a plan view of a pressure member.

FIGS. 11a, 11b & 11c are graphs of different pulse cycles obtainablewith the pulsator of the present invention.

The timing chamber 1, is cylindrical in shape and has an exernal nozzle29, giving connection to the vacuum/air phases controlled by the rateadjusting needle valve 19, and the ratio adjusting needle valve 21.

The fabricated housing includes the timing chamber 1, a body 2, and base3, having a permanent connection to vacuum 4, and a connection 5, to themilking machine teat cups.

A diaphragm 6, located in the section between the chamber 1 and body 2and capable of being sealed by the timing chamber 1. An annular seat 7,and a pressure member 8, is interposed in the chamber between theconnection to vacuum 4, and the connection to teat cups 5, and isslidable in the guide 9. The pressure member 8, is arranged to be incontact with both the diaphragm 6, and the central seating arrangement7.

The lower section of the pressure member 8 also acts as a valve memberin contact with a valve diaphragm 10 located in the base of the pulsator3 functioning to operate immediately the pressure member 8 is moved downunder atmospheric pressure on the diaphragm 6 so as to prevent directpassage of atmospheric air to the vacuum connection during the changingphases of the pulsator from air, or from vacuum to the teat cups. Thevalve diaphragm 10 also co-acts with the seat 11 located in the base 3for admitting atmospheric air to the teat cups through connection 5.

The base 3 is circular in shape and has four holes 12 arranged centrallyto allow admittance of atmospheric air to the pulsator. Provision ismade 13 for attachment of a suitable air filter. Alternatively the airadmission holes 12 may be plugged off or omitted and replaced by asuitable connection giving the pulsator access to compressed air.

Around the holes 12 is arranged a ring or seat 11 and adjacent there-toare arranged metering holes 14 enabling atmospheric air to pass to theteat cups through connection 5. Sitting across the seat 11 is a valvediaphragm 10 held in place by a suitably fixed retaining plate 15 whichhas a central aperature 16 extending just clear of the outer peripheryof the seat 11 allowing access to the contacting valve head of thepressure medium 8. Adjacent to the aperature 16 the retaining plate hasa circular recess 17. The object of this recess is to allow the valvediaphragm to have minimal or no clearance across the seat 11 so that theentry of atmospheric air to the pulsator under pulsation is onlypossible on the air phase to cups, thus creating a positive and leakproof pulsator under all conditions of operation.

When a vacuum phase pertains to the pulsator the recess 17 operates inconjunction with the projection 8b and the recess 8c of the pressuremember 8 to give clearance across the seat 11, thus allowing atmosphericair to pass to the teat cups.

The pressure member 8 is of particular shape. The guide stem 8a beingfluted or grooved to both reduce friction and give free passage ofatmospheric air via the fluted air passages 8d from teat cups topermanent vacuum.

The lower section which operates in permanent contact with the valvediaphragm 10 is stepped in shape having a circular projection 8b and acircular recess 8c the action of which is as follows:

1. On atmosphere applied across the diaphragm 6 the resultant initialdownward movement of the pressure member 8 causes the small projection8b acting centrally on the valve diaphragm 10 to immediately close offatmospheric air across the seat 11. The further downward movementcontinuing until stopped by the recess 8c acting across the seat 11 thusproviding accurate opening of the seat 7 to permanent vacuum.

2. On vacuum applied across the diaphragm 6 atmospheric air enteringthrough the holes 12 against the valve diaphragm 10 forces the pressuremember 8 upwards to instantly close off permanent vacuum at the seat 7and at the same time forces and distorts the valve diaphragm 10 aroundthe projection 8b into the recess 8c and across into the recess 17 ofthe retaining plate 15 thus giving full clearance above the seat 11 andallowing atmospheric or compressed air to pass to the teat cups via theair metering holes 14 and connection to teat cups 5.

The graph in FIG. 11a shows a standard pulse curve with curve 50ashowing the vacuum phase and 51a the pressure phase.

Referring to FIG. 5 a housing 18 is externally and vertically attachedto the body 2 preferably having a rate adjusting needle valve 19 itsseat 20 a ratio adjusting needle valve 21 and its seat 22.

The rate adjusting needle valve 19 is connected via the duct 23, channel24 and the duct 25 to the vacuum/air phases of the pulsator and thencevia the needle valve 19, the common chamber 26 nozzle 27, flexible tube28 to the nozzle 29 directly connected to the timing chamber 1.

The function of the rate adjusting needle valve is to control the rateat which air passes to and from the timing chamber. The greater theopening the faster the pulsation rate. The smaller the opening theslower the pulsation rate.

The ratio adjusting needle valve 21 (FIG. 5) is connected via thechamber 30, the duct 31, the common chamber 26 and thence via thenozzles 27 and 29 to the timing chamber 1. It also has connection viathe duct 32 and channel 33 to permanent vacuum pertaining at the duct 34or to atmosphere via the port 35 either of which may be alternativelyplugged off by the removable plug 36 according to the particular ratiorequired. If a longer vacuum phase is required the removable plug 36preventing the admission of atmospheric air through the port 35 isremoved and inserted into the channel 34 connecting permanent vacuum viathe ratio adjusting needle valve 21 to the timing chamber 1. Thisincreases the length of the vacuum cycle whereas connection to permanentvacuum lengthens the pressure cycle of the pulsator.

The ratio needle valve is now opened to admit sufficient atmospheric airto the timing chamber 1 to give the required longer vacuum phase to theteat cups.

FIG. 11c shows the longer vacuum phase 50c as against the pressure phase51c.

This is engendered by the extra time the vacuum bleed via the rateadjusting needle valve 19, the nozzles 27 & 29 to the timing chamber 1takes to remove sufficient air to enable requisite vacuum to pertain inthe timing chamber to facilitate the following air to cups phase.

To shorten the vacuum to cups phase atmospheric air is shut off byreversing the plug 36. The open duct 34 now gives an added vacuum bleedvia the channel 33, duct 32, the adjusted ratio needle valve 21, chamber30, duct 31, common chamber 26, nozzles 27 & 29, to the timingchamber 1. This in conjunction with the vacuum pertaining through therate adjusting needle valve 19 to the timing chamber 1 causes vacuum toattain quickly in the timing chamber with resultant longer air phase tothe teat cups.

FIG. 11b shows the short vacuum phase 50b and the long vacuum phase 51b.

With the plug 36 inserted into the port 35 and the ratio adjustingneedle valve 21 closed, the standard ratio of the pulsator pertains.

When it is required that the pulsator as described, also orindependently, act as a master pulsator transmitting or relaying aspecific ratio of pulsation, the following valvular relay ratioadjustment means as shown in FIG. 6 are also suitably attached to thebody 2.

The valve housing 37 is preferably oblong in shape and is constructedwith two main air passages 38 and 39. Passage 38 incorporates preferablya ball valve 40 and its seat 41. The upward movement of the ball iscontained and controlled by the adjustable coned retaining screw 42.

Passage 39 incorporates and is controlled by preferably a needle valve43 and its seat 44. Both passages are commonly interconnected via thechannels 45 and 46 to both the vacuum and atmospheric air phases to theteat cups of its attached pulsator through the connection 47 and to theconnecting nozzle 48 operating to the actuation chamber to the next anddriven pulsator.

The function of the valve when used in conjunction as a master or as afixed component of a relay pulsator valve is to correct any ratio ofvacuum to atmospheric air inherent to it, to that ratio necessary forthe required operation of the relay or slave pulsators subject to it.

When used in fixed relationship as a relay pulsator subject to mastercontrol it may also be used preferably as a driving unit transmitting acorrected pulse to the next pulsator or as a driven unit correcting andoperating to the pulse received. In the latter usage the valve has noconnection to the vacuum and atmospheric air phases of the pulsator towhich it is attached. These are received from a suitable connection onthe previous relaying pulsator and connected directly to an externalnozzle on the valve housing 37 giving access to the passage 38. Thepulse corrected by the valve passes via the nozzle 48 to the actuatingchamber of its attached pulsator.

DESCRIPTION OF RELAY PULSATOR VALVE. FIGS. 3, 4, 6, 7 & 8.

The construction of the relay valve is identical to that of theautomatic valve except that the rate and ratio valve is omitted, thetiming chamber 1 is replaced by the pulsator cap 50 which has preferablya nozzle connection 49 giving access to the actuating chamber 51 and therelay/ratio adjustment valve 37a is added as a combined entity.

It will be appreciated that the relay/ratio valve 37a may be added toany pulsator of the same general type.

Referring to FIGS. 3 & 4 when atmospheric air pertains to the valve viathe connection 47 air flows through passage 38 and via the ball valve 40lifted thereby, common channel 46 and via channel 45, the needle valve43, passage 39, chamber 46, through the connecting nozzle 48 to thenozzle 49 giving access through the pulsator cap 50 to the actuatingchamber 51 of the driven pulsator to provide free and rapid action ofthe diaphragm 6. The airflow or pulse thus passed causes a resultantinstant vacuum pulse to the teat cups of the driven pulsator.

Conversely, when vacuum pertains to the valve, air being withdrawnimmediately closes the ball valve 40 thus compelling all air to pass viapassage 39, the adjusting needle valve 43, channel 45, passage 38 to theconnection to vacuum 47. Vacuum now pertaining to the actuating chamberof the driven pulsator causes atmosphere to pertain to the attached teatcups.

ADJUSTMENT:

To lengthen the vacuum to teat cups phase the withdrawal of air isrestricted by closing the ratio needle valve 43 thus prolonging the airphase to the actuating chamber to the desired ratio.

To shorten the vacuum to teat cups phase the ratio needle valve isopened thus accelerating the withdrawal of air from the actuatingchamber.

DESCRIPTION OF SLAVE PULSATOR:

The construction of the slave pulsator is identical to the relaypulsator except that the relay ratio adjustment valve is omitted.

With the trend to more rapid rates of pulsation combined with increasedand increasing vacuum to atmospheric air ratios to promote fastermilking of the herd, the time factor in pulsation for the introductionof atmospheric air giving pressure to the teat cups has becomeprogressively shorter and less conducive to cow comfort and well being.

The application of compressed air to pulsators while it would accelerateand increase the pressure cycle, necessitates a pulsator essentiallycapable of having the ratio of pulsation adjustable to both the airpressure used and the rate of pulsation required otherwise advantagegained could be largely negatived by pressure induced ratio imbalance.

The claims defining the invention are as follows:
 1. A relay valvecontrol means for transmitting pulses of vacuum alternately withnon-vacuum pulses between a pair of pulsators, each said pulsatorcomprising a body including means for connecting a first zone of saidbody to a permanent vacuum source and a diaphragm valve comprising afirst valve element cooperating with a first valve seat adapted toconnect a second zone of said body to a non-vacuum source of air, saidbody further including a second valve seat adapted to be opened orclosed to establish or prevent communication between said first andsecond zones, said body further housing a first deformable diaphragmhaving first and second opposed surfaces with said first surfacearranged for exposure to said permanent vacuum source and cooperatingwith said first valve element whereby said first valve element ismovable such that said first valve seat is open for at least a majorportion of the time during which said second valve seat is closedthereby applying non-vacuum air to said second zone, and when saidsecond valve seat is open, said first valve seat is closed therebyapplying vacuum to said second zone, said relay valve control meansenabling communication of the second zone of one of said pulsators withthe second surface of the first deformable diaphragm of the other ofsaid pulsators, said communication occurring via a non return valve andan adjustable valve means arranged in parallel flow relation.
 2. A relayvalve control means according to claim 1 wherein said non-vacuum sourceof air is atmospheric air.
 3. A relay valve control means according toclaim 1 wherein said non-vacuum source of air is compressed air.
 4. Arelay valve control means according to claim 1 wherein said first valveelement comprises a second deformable diaphragm secured to said body. 5.A relay valve control means according to claim 1 wherein said relayvalve control means is also arranged to communicate said second zone ofthe pulsator with the second surface of the first deformable diaphragmof said pulsator.
 6. A relay valve control means according to claim 1further including a movable valve member interposed between saidcooperating with said second deformable diaphragm and said firstdeformable diaphragm, said valve member including a seal surface adaptedto engage against said second valve seat to close said second valveseat.
 7. A relay valve control means according to claim 6 wherein saidsecond valve seat is closed prior to said second diaphragm opening, saidfirst valve seat and said second diaphragm closes said first valve seatprior to said second valve seat opening.
 8. A relay valve control meansaccording to claim 7 wherein said valve member includes a projectionadapted to engage and press said second deformable diaphragm againstsaid first valve seat prior to engagement of a second portion of saidvalve member pressing against said second deformable diaphragm on saidfirst valve seat.
 9. A relay valve control means according to claim 6wherein when said valve member is engaged against said second valveseat, a clearance zone is formed above said first valve seat into whichsaid second diaphragm is deformable under action of vacuum in saidsecond zone to open said first valve seat permitting air to flow intosaid second zone.
 10. A relay valve control means according to claim 1wherein said relay control valve means comprises a body having a inletpassage communicating with the second zone of said pulsator, said inletpassage communicating via a non return valve with an outlet passagewhich is adapted for communication with the second surface of the firstdeformable diaphragm of the adjacent pulsator, said relay control valvemeans further includes a branch passage leading from said inlet passageto said outlet passage, flow through said branch passage beingcontrolled by an adjustable valve element.
 11. A relay valve controlmeans according to claim 10 wherein said outlet passage is also arrangedfor communication with the second surface of the first deformablediaphragm of the pulsator to which the relay control valve means isconnected.
 12. A relay valve control means according to claim 1 whereinsaid relay control valve means comprises a body having an inlet passagecommunicating with the second zone of said pulsator, said inlet passagecommunicating via a non return valve with an outlet passage which isadapted for communication with the second surface of the firstdeformable diaphragm of the pulsator to which the relay control valvemeans is connected, said relay control valve means further including abranch passage leading from said inlet passage to said outlet passage,flow through said branch passage being controlled by an adjustable valveelement.